In the existing mobile communication terminals, terminals with dual-mode, dual-card and dual-standby functions have gradually appeared because local number portability (LNP) is not offered to users and users do not want to discard the old number. But due to the issue that the current Code Division Multiple Access (CDMA) and Global System for Mobile communications (GSM) cannot support multiple channels of call waiting, there is no full-sense CDMA&GSM/wideband Code Division Multiple Access (WCDMA) dual-mode, dual-card and dual-standby mobile communication terminals in the market yet.
From the technical implementation standpoint, there are currently mainly the following two CDMA and GSM/WCDMA dual-mode, dual-card and dual-standby terminal implementation schemes in the market.
The first one is implemented by using one set of chipsets, that is, there is only one set of baseband chips and radio frequency chips in the phone, the radio frequency chips detect the CDMA and GSM/WCDMA network signals with the polling method to achieve the dual-mode, dual-card and dual-standby, but this physical restriction on hardware cause that it can only achieve a single channel under the two network modes, that is, when there is a call in progress in either mode, no call can be dialed out or no new incoming call can be answered in the other mode.
The second one is implemented by using two sets of chipsets, that is, the mobile phone is equipped with two sets of baseband chips and radio frequency chips, which is equivalent to combine two entire mobile phone motherboards together and place them in the same mobile phone housing. Such an implementation can support both User Identity Model (UIM) and Subscriber Identity Module (SIM)/Universal Subscriber Identity Module (USIM) working simultaneously. However, even for the terminals using two sets of baseband chips and radio frequency chips in the current market, they basically just realize the simplest dual-channel, that is, when there is a call in progress in either mode, if a call needs to be dialed out or a new incoming call needs to be answered in the other mode, the call in progress in the previous mode must be hung up.
In short, the CDMA and GSM/WCDMA dual-mode and dual-standby mobile terminals implemented in the related art have the following limitations:
although terminals implemented with the abovementioned first scheme achieve the dual-standby function, but the dual-channel cannot be achieved, when there is a call in progress in either mode, the other mode cannot work, and a call can be easily missed; and although terminals implemented with the abovementioned second scheme achieve the dual-standby and dual-channel function, such terminals only realize the simplest dual-channel, but do not support calling in both modes simultaneously, even a small number of terminals support calling in both modes simultaneously, there is not any processing on the case of multiple CDMA or GSM/WCDMA calls, and the user experience is poor.